Tag Archives: spine

Assembling Tapejara wellnhoferi

This weekend I traveled to Uberaba, MG, Brazil, where I installed this replica of a Tapejara wellnhoferi. I traveled with more than 190 individual unassembled bones. Arriving there I had three days and a half to put them together and assemble a Tapejara wellnhoferi pterosaur in a flying position. All the 196 bones are in this 16×23 cm box.

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The skeleton was installed in a museum which is part of a cultural and scientific complex in the town of Peirópolis. It will be displayed in one of the museums in the complex.

Peirópolis is a small town located 20 km away from the city of Uberaba (pop. 300 000) in the state of Minas Gerais, Brazil. The whole area is situated over a geological formation from the late Cretaceous and contains several paleontological sites where hundreds of fossils, mostly reptiles, were found.  The Peiropolis Dinosaur Museum (Museu de Dinosauros) is part of a scientific and cultural complex (Complexo Cultural e Científico de Peirópolis – CCCP) which also includes a research center (Centro de Pesquisas Paleontológicas Llewellyn Ivor Price) and another smaller museum installed in an old train station. The complex is administered by the Federal University of Triângulo Mineiro (UFTM).

The smaller museum contains only species which were found locally; another contains replicas and fossils from other parts of the country. This Tapejara is the first pterosaur that will be on display in the complex.

Besides installing the Tapejara, I also gave a small workshop showing how I researched, planned and created the individual bones from sheets of foam, demonstrating the techniques and materials used. In the end, I recycled a small tray by cutting two pieces to make a Tapejara humerus.

Assembly took me 3 and 1/2 days. It took long because I used silicone rubber to attach the bones together and its only completely dry in 24 hours (before that it gets gradually stronger, but it may tear easily.) I also used part of the first day to photograph each of the bones and weigh them. The whole collection weighs only 300 grams!

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But before turning those bones into a Tapejara, I decided to turn them into a fossil first. This is a representation of the limestone slab which contains one of the most complete specimens: SMNK PAL 1137 (see “Eck et al, 2011, On the osteology of Tapejara wellnhoferi …”). The actual slab contains bones from three individuals, but I only have one so there are some bones missing. Anyway, here is SMNK PAL 1137 assembled with replicas of bones from one Tapejara:

smnk

I started with the head (I used some of these pictures to illustrate the previous post). The neurocranium is attached dorsally to the upper crest (with silicone rubber “cartilage”, but shown below with pins) and at the anterior part of the orbits through the lacrimal bone (shown detached in the next two pictures, and attached with silicone rubber and two pins in the third).

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The spine has a long rubber tube acting as a medulla. Here is the Tapejara with an assembled skull and spine (cervicals, dorsals, sacrum and tail). The quadrate bones, that articulate with the jaw, are shown below beside the skull and were not attached yet.

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The next step is the assembly of the pelvis. Each bone was attached with silicone rubber, keeping it firmly in place while allowing some elasticity between the bones. Silicone rubber acts like cartilage. Below are some photos of the complete pelvis showing the sacrum, gastralia, pre-pubis, pubis, ischium and ilium (preacetabular and postsacetabular processes).

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I was hosted by friends in Uberaba, and hanged the skeleton every night in my bedroom window. This is my window after the first day.

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On Saturday I returned to the museum and assembled the feet, legs, part of the wings and part of the pectoral girdle. Here’s a pair of Tapejara feet. The bones are firmly attached but they retain some flexibility. You can pass your fingers between Tapejara’s toes.

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My table of bones.

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Here are some views of the skull after I attached the mandible. The pins are holding it closed because I only added silicone rubber to the joints. When the silicone dries, the weight of the lower jaw should keep the mouth slightly open.

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It’s easier to work on the ribs by hanging the skeleton. I attached practically all the ribs and the sternum (through four pairs of sternal ribs).

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And this is my window after day 2.

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On day 3 I occupied the kitchen at my friends’ place, and finally finished the pectoral girdle, connecting the vertebral ribs to the sternal ribs, and to the sternum and gastralia.

I didn’t use cartilagenous connections from the posterior vertebral ribs to the gastralia, nor did I leave them floating in the air. I used thin sternal ribs as placeholders since I had some spare ones. My intention was to remove them later, when the abdomen had dried and was strong enough, and replace them with pure cartilage to connect to the gastralia, but I forgot to do so. It’s not completely inaccurate the way it is (no fossil evidence against it – but perhaps the “floating ribs” should be smaller). Anyway, I can consider fixing that when I return to Uberaba and have an opportunity to review the replica.

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Here is a view from the front showing the scapulocoracoid.

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The limbs are almost done. This photo was taken just before connecting the carpals and fingers.

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Oh, and this is Samuel – a Felis catus. He is always with me in the kitchen observing the Tapejara wellnhoferi. It probably looks like a big tasty bird for him.

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Here is the finished Tapejara body. As you can see I used “sternal” ribs to connect gastralia (the last three ribs) to the vertebral ribs.

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There is not enough space on this table for a pterosaur.

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Almost done. Now some fingers.

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A pterosaur hand. That long fourth dactylus is the pterus 🙂

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And this is the end of day 3. All the small parts assembled into larger ones. I arrived in town with 196 parts, now I have six parts hanging in my window. I couldn’t assemble it all because it woundn’t  fit in the car.

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Monday morning. Tapejara for breakfast.

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This is my host Regis. He is a musician and plays the guitar in a heavy metal band. This time, instead of a guitar, he holds a Tapejara. And the cat on the couch is one of the daughters of Samuel the cat.

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Samuel was watching the skeleton on the kitchen table a while ago.

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Finally assembling the Tapejara at the Peiropolis Dinosaur Museum. It will stay in this room (which contains several skeletons that are not yet on display) until it is installed. Here I hanged the body, head, a leg and a wing.

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And this is the final result.

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Hmmm… It might need some chiropractic therapy for that scoliosis.

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Looks good, but the posture is still not right.

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That’s not a good posture for the neck!

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It should be facing down slightly. Like this.

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Now it’s much better.

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And that’s it! Now there is a Tapejara in the Peiropolis Museum. It will still receive a coating of matte varnish, and then it will be displayed in the main hall of the museum, near the big dinosaurs. If you ever go to Uberaba, check it out!

As in any project like this, there are some adjustments that can still be made, improvements in posture and eventual fixes that might have to be done in the future. If I have the opportunity to do so, I will review the replica next time I am in Uberaba. Some improvements that may be done very easily include 1) straightening the gastralia axis (it’s making a curved line), 2) reducing slightly the curvature of the back (it should be curved, but perhaps it was too much – that might be causing the curvature in the gastralia axis), and 3) removing sternal ribs connected to gastralia (or maybe simply trimming them).

This was the Imaginary Pterosaur #7: Tapejara wellnhoferi, the first one I made for a museum. It was commissioned work and I started it two months ago, working on it about half of that time, traveling with it and working on it in different cities. Although I made all the bones by myself, I had help from many people. First of all I would like to thank the paleoartist Rodolfo Nogueira for introducing me to the director of the Peirópolis Cultural and Scientific Complex, Vicente Antunes, who had told him that he wished to have a pterosaur on display in the museum; the staff at the museum and UFTM, specially the researchers Thiago Marinho and Agustin Martinelli, who first contacted me and led the process that allowed me the opportunity to create this replica for the museum. Several other researchers helped me with photographic sources, articles and paleontological information: Hebert Bruno Campos, Felipe Pinheiro, and specially Brian Andres who gave me access to many photographs and measurements that were critical to the accuracy of this replica. Finally I must thank the family who hosted me in Uberaba: Alípio, Regis, Ludmila and Lucia (and their many cats) for their fantastic hospitality, for dedicating time and effort to make my stay as comfortable as possible, for driving me to Peiropolis and back (40km!) and even letting me occupy their kitchen table during three days, turning it into a pterosaur assembly lab! 

Now I will stop making pterosaurs for about a month and a half because I will travel to Europe (Spain, Portugal, England and Russia). When I return, I will probably start Imaginary Pterosaur #8.

I will publish one more post on Tapejara with statistics (weight, dimensions) and links to pictures of all the parts.

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Tapejara: pelvic girdle

I already had made the pelvic bones, but the sternum complex was missing. I didn’t find any realiable source with a perfect sternum, so I used as a source the same azhdarchoid sternum that I used in Tupuxuara, and adjusted it so it would fit the Tapejara pelvis (from SMNK PAL 1137). They are 5 sacral vertebrae, and two dorsal ones with lateral processes fused to the preacetabular processes of the ilium.

I cut it out in one piece from a sheet of 2mm foam, and added the stacked vertebral bodies sculpted out of thicker (yellow) foam. Here are two views of the sacrum after treating with fire.

sacrum 2 sacrum 1

Four views of the finished sacrum.

lateral ventral posterior anterior

Next step: assemble the pectoral girdle. I now have all the parts.

parts

I wish I had smaller pins.

testing dorsal dorsal w pelvis testing lateral anterior with pelvis posterior with pelvis

I placed a rubber tube through the vertebrae acting as a spinal cord. It will be used to attach the pelvic girdle to the dorsal spine and to attach the tail on the other side.

ventral w pelvis

I now can test all the connections. Here is the Tapejara dressed in its pelvic girdle.pelvis and sacrum

A dorsal view.

dorsal assembly

And a ventral one. It’s almost finished. I’m already prototyping the pre-pubis and gastralia, but before I assemble the rest I will cover what I have so far with epoxi resin (I can’t use pins anymore).

ventral assembly lateral assembly

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Tapejara: pectoral girdle

The pectoral girdle consists of scapula, coracoid, sternum, dorsal vertebrae and ribs that grow from the vertebrae and from the sternum. I’m still having trouble figuring out how to assemble the scapula and coracoid. I read some articles and I haven’t discovered yet what most paleontologists think is the best layout. They seem to disagree in many aspects. Without twisting the bones quite a bit or setting the scapula to articulate with the first two dorsals I can’t obtain a low position. At best, the glenoid will stay somewhere in the middle of the chest. For now, I just pinned the proximal end of the scapula to the third dorsa, and the distal end of the coracoid to the sternum, so I could work on the rest of the pectoral girdle. But the correct way to connect scapula and coracoid is still an issue I haven’t resolved. Any help is welcome.

The ribs. I found some random ribs in fossils, but I preferred to use Wellnhofer’s reconstruction of Pteranodon as a reference to start with. I scaled them for Tapejara and made these sketches.

rib cut out

I cut out the two first pairs.

rib cut out 2

I made them hollow of course. This is a first prototype attached to the first dorsal vertebra.

rib testing

I quickly made some (generic) sternal ribs and connected their ends to the sternum and larger ribs to test the shape of the rib cage.

girdle testing girdle testing 3

Time to make more ribs.

more cut outs 2 first rib set

testing

The sternal ribs are thin but they have some lateral very thin bone pieces projecting laterally. It looks like some kind of ossified cartilage. How many ribs should be connected to the sternum? Some say seven lateral pairs, many reconstructions show four or five. The azhdarchoid MN-6588-V seems to have seven, and probably two more pairs behind. I chose five.

sternal ribs 2

Now the challenging attempt to assemble the pectoral girdle.

pectoral assembly parts 2

Somehow I fitted the scapula and coracoid in a way that revealed a glenoid and didn’t seem weird. The proximal end of the scapula is pinned to the third dorsal vertebra. If I project it a bit more laterally, it can move back more, but the sternum-coracoid articulation will also change.

ventral body 2

So now it looks like this.

ventral body lateral body

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Tupuxuara: the pelvis, sacrum and dorsal vertebrae

The specimen I have been using as a source (IMNH 1052, Iwaki Museum, Tokyo) has no pelvis, sacrum or any other dorsal vertebrae. I already made all the bones from that source. The sources I used for this pelvis were kindly sent to me by Mark Witton, and belong to a related species (possibly a Tupuxuara).

My sources were four views and a diagram from where I calculated the size of the pelvis relative to the other bones. The right view was the best, so I used it to sketch the pelvis bones. I sketched the sacrum from the dorsal view. There was also a posterior view, which I used later.

sketch

I cut the parts slightly larger so they could be molded.

cut

First, I assembled the sacrum gluing the two halves together (by the spinal crest).

assemble_sacrum

Then some trimming, and let it dry.

attach_sacrum

I was in a hurry to see what the pterosaur would look like with a pelvis, so I pinned the parts together and let the sacrum dry hanging on its “spinal chord”.

test

Then I added some foam to the other side, to shape the sacrum, and compared it to a diagram I made from the sources.

sacrum_1

While that was drying, I worked on the sacral and dorsal vertebrae, carving a spine from thick foam. Here I lined up the sixth thoracic vertebra (the last one from the notarium), three free lumbar (dorsal) vertebrae, and seven fused vertebrae.

dorsal_sacral

vertebra_sacral

I tested it before attaching the parts.

test_sacrum

I had no source for the three lumbar vertebrae, so I invented them based on the others.

dorsal_start

Here are the vertebrae lined up.

dorsal_test

And here is the first one that articulates with the pelvis in place.

dorsal_foam

As a spinal chord I am using plastic tubes of different widths. I insert the thin ones into the wide ones. There is a spinal chord for the cervicals, for the notarium and for the pelvis. The tail vertebra will be mounted on a thin rigid plastic spinal chord, which will be inserted in the thinner tube (the white one in the picture below).

sacrum_2

Time to attach the pelvis. First one side.

pelvis_side

Then the other. I always twist and fold the foam before attaching.

pelvis_both

Some parts need more work. Here I am trying to shape the pubis while keeping the ischium in place.

ischium

The two halves are not enough to provide all the three-dimensional details I need for the pelvis, so I made some “masks” with 5 mm foam which will allow some shaping.

masks

I also added some foam at the sides of the ilium to shape a small iliac crest (extending from each side of the sacrum). From the pictures I don’t know the exact shape of the ilium (I have no frontal view, and it’s partially damaged), so I looked at some other pterosaurs and chose something which matched the picture. This is the pelvis seen from the inside after most of the foam shaping.

front_foam

Another view.

sacrum_all

And here’s a dorsal view.

top_foam

Now the resin coating, coffee staining, and we’re done. Here are three views of the pelvis. This is the left side.

side

This is a dorsal view.

dorsal

And this is a ventral view.

ventral

The pelvis is a complex set of bones. I don’t know if I achieved in making an accurate one. I did my best with only three views. I’m not really sure if I should have closed the ischium. If I get more data in the future I will fix any mistakes.

Here you can see it in other angles.

ischium_done

angle_ventral

pubis_close

angle_ventral_2

dorsal_close

Now finally I can attach the legs. Here are two pictures of the pelvis in place with the femora attached.

connected

from behind

This is what it looks like when you are underneath a pterosaur skeleton.

under

It saw us and it’s coming this way!

almost done

What’s next? I don’t know. As you can see from the pictures above, some bones are connected with rubber bands: I still didn’t make any carpals. I will have to invent carpals, fingers, toes, and tails. I have none of them. They are small and simple bones, so there is a good chance that I might finish this skeleton tomorrow.

I already have some sources but I am still interested in any new ones. If I have more information I will be able to make a more accurate model. I am interested in pictures or drawings of feet, tails or hands of a Tupuxuara, Thalassodromidae, or even a related species. If you have any, send me an email!

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Tupuxuara’s shoulders: the scapulocoracoid

In humans, the bone that connects the scapula to the sternum is the clavicle. Most other vertebrates have coracoids connecting scapula to stern (although they may also have articulating clavicles). Humans, marsupials, and mammals that don’t lay eggs do not have coracoids (but they do have a small hook in the upper scapula which is called the coracoid process). Birds and pterosaurs which require a strong shoulder girdle to support the wings have the scapula and coracoid bones fused together. This bone is called the scapulocoracoid.

The Tupuxuara specimen at the Iwaki Museum in Japan has one well preserved scapulocoracoid (as far as I know: I only have the pictures), so I used it as a model for both left and right scapulocoracoids.

cut

My sources are only four views of the scapulocoracoid (two sides, inner and outer views). It would be best to have at least six, and some photos in different angles as well, but from these sources I could infer the shape of the bone to start making it and later make any necessary adjustments. From the outer and inner views it seems that the scapulocoracoid has the twisted shape below, when seen from the side that connects to the arm.

twist

The place where the two flat long bones are fused together is full of details which aren’t so easy to see from the photos. I cut out the general shape in thick foam using the side views as a reference.

connection

Then I cut it again (since the base is not flat), trimmed the parts so they would fit well and pasted it onto the scapulocoracoid shaped foam strip. The next step is to shape the coracoid and scapula bones. I started adding strips of foam (since I will make it hollow.)

foam1

I reinforced both long bones with a thin (3mm) somewhat flexible wooden stick inside, along the length of the bone. I didn’t photograph it. The photo below shows both scapulocoracoids almost finished.

foam2

This is the right scapulocoracoid just before finishing with fire.

right_foam

And this is the left scapulocoracoid after the fire sculpting.

left_foam

Here are both of them:

finished_foam

testing_foam

After that, I added a layer of acrylic resin (modelling paste) and tried to mount the pectoral girdle. But… which side is the coracoid and which side is the scapula? The part I thought was the coracoid seemed too short, so maybe it’s the other way around.

AorB

I lack experience in vertebrate anatomy, so I needed to do some research. I discovered that, unlike Guidraco, Anhanguera and other Ornitocheirids, Tupuxuara has a shorter coracoid (like Tapejara and Azhdarchids). In Anhanguera the shoulders would be placed near the back, where in Tupuxuara they should be closer to the front. The pictures above are not precise since I still had to adjust all the parts, but it seems that the correct placement is the second. The first assembly places the scapular bones almost perpendicular to the notarium (that’s why in ornitocheirids there sometimes is a depression on the the vertebra’s spinal process.) For the second one to work, the scapulas have to move back more and barely touch the spine at an angle (45 degrees or more). I am still not sure about all of this and will do more research before attempting to assemble it.

Here are the pictures of the finished scapulocoracoids.

back

bottom

front

top

Since this is a very complex bone to grasp from photos, it’s good to have views in other angles.

angle1

angle2

outside

I still can’t assemble the full pectoral girdle connecting the stern and notarium. I made the first vertebra too wide and will have to remove at least 1 cm from each side. But I was able to test the connection with the stern. Here are some pictures (I didn’t double check and don’t really know if this is the right way to do it, but it seems to fit nicely).

girdle_back

girdle_bottom

girdle_front

girdle_side

girdle_top

The two pieces below should fit together nicely, but they don’t because of a problem in the larger vertebra. I will have to fix that before assembling the pectoral girdle.

girdle_notarium

But I tried anyway (it’s made of foam, so I can always squish it a bit :)) The pectoral girdle will look something like this when finished:

neck_mount

head_mount

Tupuxuara now has shoulders. Now we need to connect some arms to them. Tomorrow we will make two humeri.

side_head

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Tupuxuara: thoracic vertebrae and the notarium, part 2

orphan_w_pterosaur

I finished the first two thoracic vertebrae, which completes the notarium. This is vertebra no. 2 before covering with arcylic resin.

v2_foam_detail

Here it is after the resin and coffee stains, in place with vertebra no. 1 which is still under construction.

v1_fit

I had a good frontal view of vertebra no. 1, since it is the first one in the notarium. Here I am working on the rib (which is hollow).

v1_3D_ribs

Vertebra no. 1 required a lot of work, and adjustments. These are views from the front and back before adding the layer of resin.

v1_foam_front

v1_foam_back

Here are views of the six thoracic vertebrae disconnected. This is the rear view.

all_back

And this is the front view.

all_front

I won’t permanently connect the bones yet. This is a dorsal view of the notarium:

notarium_dorsal

And a ventral view:

notarium_ventral

And here are some pictures of the notarium connected to the neck.

connected_dorsal

connected_side

connected_ventral

neck_and_thorax

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Tupuxuara: thoracic vertebrae and the notarium, part I

lab

I have six photos of the notarium: the six thoracic vertebrae fused together at the pterosaur’s back. I have no photos of the individual vertebrae, and since I want to have as much detail as possible I used other photos of other notariums and thoracic vertebrae as a reference. I also inferred vertebral shape by looking at the last cervical vertebrae of the Tupuxuara.

I started carving the notarium in one piece.

notarium_start

Then I started adding details on the sides with strips of foam.

flaps

After that, I separated the vertebrae.

split

The specimen I am using as a reference has no ribs on the last two thoracic vertebrae, but that doesn’t mean it did not actually have ribs. I might add them later. The photo that shows the notarium seen from behind reveals details of the last vertebra. So I worked on these two first.

last two

Then I started working on vertebrae three and four.

three and four

Here are some pictures of the unfinished notarium without any ribs.

testing

testing w cerv

Testing the connection to the rest of the spine:

testing_neck

And checking what it will look like when connected to the rest of the pterosaur.

testing_skull

It’s easier to add details to vertebrae 3 and 4 with the ribs in place. I made them hollow, using two halves of foam, and using smaller bits of foam to fill the gaps, add detail and strengthen its base. I then connected the notarium together to compare with the photos.

with four

Here are the last four thoracic vertebrae of the notarium seen from the back. I still need to fix some details.

four

Now I started working on the first and second vertebrae. This is part of vertebra no. 2.

number two

And here vertebra no. 2 with a bit more detail.

two

Now I can test the connection of the whole notarium.

bottom_ribs

side_ribs

top_ribs

The shape still does not match the photo. I have to do some twisting, cutting and reshaping before finishing. In the next post I will show the complete notarium.

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